Part of staying at the top means that, as the years' pass, Rossi has to work a lot harder away from the race track.

"You have to work a lot at home, try to train every day with the motorcycle but also the gym. But I don't think it will change a lot between 40 and 36, but for sure it changes a lot between 40 and 25," he said.

"So you have to work harder [as you get older] but anyway it's possible."

Rossi suffered his first ever winless season with Yamaha in 2018, but still finished as the factory's top rider with third place in the world championship.

The 115-time grand prix winner hopes he will continue to race long enough to compete against brother Luca Marini, a winner in Moto2 last season.

"Yes, I hope to race together with my brother. I hope that Luca can be strong this year in Moto2 and maybe he can arrive in MotoGP before I stop. That would be good to race together. It would also be something that, sincerely, I never expected. Nobody expected!"

Whenever Rossi does finally hang up his leathers, there has been talk of moving his VR46 team into MotoGP. But Rossi also has his eye on competing in a number of stand-out car races, including perhaps the Dakar rally.

"When I will stop with the MotoGP, I want to try to continue with the cars because it's my great passion," he said.

"The Dakar is a very interesting race. So why not? I mean it's very hard, difficult, so you have to prepare in a good way but I'm curious to try one time. Maybe it can happen…"

And what about a potential third generation of Rossi grand prix motorcycle racers, which began with Valentino's father Graziano in the late 1970s.

"For sure, if I will have a son I'd be happy if he raced motorcycles. But, you know, I cannot choose; it would have to be his choice."

Rossi will continue preparations for the 2019 MotoGP season with official testing at Sepang in Malaysia later this week.

The oldest riders that have won 500cc/MotoGP races (all before Rossi was born!)